Acoustic Telemetry For Monitoring An Annulus Between The Production Casing And The Next Outer Casing Of A Well

ABSTRACT

A tool is positioned inside a production casing in a well such that at least one acoustic telemetry device provided in an extendable arm of the tool is located less than six inches away from at least another acoustic telemetry device provided in a casing module. Such proximity can ensure that the acoustic signals can be transmitted between acoustic telemetry devices through the production casing. The tool identifies a condition in the well that is measured in the B-annulus between the production casing and a next outer casing. In turn, the tool broadcasts the measured condition in the well to the Earth&#39;s surface where the measurement can be used to inform a decision about the well.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. provisional application Ser. No. 63/104,280, filed on Oct. 22, 2020, which is incorporated herein by reference for all or any purposes.

BACKGROUND

This disclosure relates generally to an acoustic telemetry system and a method of acoustic telemetry for transmitting signals from a sensor that monitors a condition in a well outside a casing. The acoustic telemetry system and the method of acoustic telemetry can more particularly be used with a sensor that monitors a condition in an annulus between a production casing and a next outer casing of the well, often referred to as the B-annulus. In some embodiments, the condition may be pressure.

Inductive coupling is known to be capable of wirelessly transmitting data gathered by a sensor, typically a pressure gauge, through the casing. However, inductive coupling is expensive. Alternatively, the data gathered by the sensor can be broadcasted to the surface using Electro-Magnetic (“EM”) transmitters located outside of the casing. However, multiple antennae must be spread out at the surface to receive the EM signal. Also, it is difficult for Electro-Magnetic waves to propagate through some Earth formations or water. In yet another alternative, US Pub. No. 2016/0215612 discloses a series of communication nodes and associated pipe joints, such as production casing joints. The communication nodes can be designed to be pre-welded onto the pipe joint wall, glued to the wall using an adhesive such as epoxy, or selectively attachable to/detachable from the pipe joint by mechanical means such as clamps. The communications nodes include an elongated body that supports one or more batteries and a transmitter. In some examples, the transmitter is designed to send acoustic signals to a receiver that resides in the well. However, the receiver may need to be in proximity of the transmitter for picking up the transmitter's acoustic signals because the acoustic signals attenuate rapidly when they travel away from the transmitter. In practice, it may be challenging to position the receiver sufficiently close to the transmitter because the positioning is performed from the Earth's surface, which is sometimes miles away from the receiver.

Thus, there is a continuing need in the art for a telemetry system and a method of telemetry for transmitting signals from a sensor monitoring a condition in a well outside a casing, such as in an annulus between a production casing and a next outer casing.

BRIEF SUMMARY OF THE DISCLOSURE

The disclosure describes an acoustic telemetry system, which may be used for transmitting signals from at least one sensor. The acoustic telemetry system may comprise a tool conveyable inside a casing of a well and at least one casing module.

The tool may include an arm coupled to the tool and at least one first acoustic telemetry device mounted on the arm. The first acoustic telemetry device may be capable of receiving acoustic signals from a second acoustic telemetry device. The arm may be extendable from the tool toward an inner surface of the casing such that the first acoustic telemetry device is pressed against the inner surface of the casing. Optionally, the first acoustic telemetry device may also be capable of emitting acoustic waves.

The casing module may include the sensor and the second acoustic telemetry device. The sensor may be capable of measuring a condition in the well outside the casing. The second acoustic telemetry device may be capable of transmitting acoustic signals indicative of the condition in the well, as measured by the sensor, through the casing, and to the first acoustic telemetry device. The second acoustic telemetry device may be pressed against an outer surface of the casing. Optionally, the second acoustic telemetry device comprises a piezoelectric material. The second acoustic telemetry device may also be capable of converting the acoustic waves into a DC voltage. The casing module may further include a rechargeable battery or a capacitor coupled to the DC voltage. The sensor may be powered by the rechargeable battery or the capacitor.

In some embodiments, the tool may include a plurality of arms and a corresponding plurality of first acoustic telemetry devices. Each of the plurality of first acoustic telemetry devices may be similar to the first acoustic telemetry device described hereinabove. Each of the plurality of arms may be similar to the are described hereinabove. The plurality of arms may be positioned around a periphery of the tool.

In some embodiments, the arm or the plurality of arms may include several acoustic telemetry modules positioned along a longitudinal axis of the tool, and the arm or the plurality of arms may be extendable from the tool toward the inner surface of the casing such that each of the several acoustic telemetry modules is pressed against the inner surface of the casing. Each of the several acoustic telemetry modules may be similar to the first acoustic telemetry device described hereinabove.

In some embodiments, the acoustic telemetry system may comprise a plurality of casing modules. Each of the plurality of second acoustic telemetry devices may be configured to transmit acoustic signals indicative of the condition in the well. Each of the plurality of second acoustic telemetry devices may be pressed against the outer surface of the casing. The plurality of second acoustic telemetry devices may be positioned around a periphery of the casing. Optionally, each of the plurality of casing modules may include a corresponding one of a plurality of sensors. Each of the plurality of sensors may be similar to the sensor described hereinabove. Each of the plurality of second acoustic telemetry devices may be configured to transmit acoustic signals indicative of the condition in the well measured by the corresponding one of the plurality of sensors.

The disclosure describes a method of acoustic telemetry, which may be used for transmitting signals from a sensor. The method may comprise the step of positioning a tool similar to the tool described hereinabove inside a casing of a well. Preferably, the tool may be positioned inside the casing of the well such that at least one of the first acoustic telemetry devices is located less than six inches away from a second acoustic telemetry device and/or at least one of the plurality of second acoustic telemetry devices is located less than six inches away from the first acoustic telemetry device.

The method may comprise the step of extending the arm from the tool toward an inner surface of the casing such that the first acoustic telemetry device is pressed against the inner surface of the casing. In embodiments where the tool includes a plurality of first acoustic telemetry devices mounted on a respective one of a plurality of arms, the method may comprise the step of extending each of the plurality of arms from the tool toward the inner surface of the casing such that each of the plurality of first acoustic telemetry devices is pressed against the inner surface of the casing. In embodiments where the arm or each of the plurality of arms includes several acoustic telemetry modules positioned along a longitudinal axis of the tool, the arm or each of the plurality of arms is extended from the tool toward the inner surface of the casing such that each of the several acoustic telemetry modules is pressed against the inner surface of the casing.

The method may comprise the step of measuring a condition in the well outside the casing with a sensor included in a casing module similar to the casing module described hereinabove. In embodiments where each of the plurality of casing modules includes a corresponding one of a plurality of sensors, the method may further comprise the step of measuring the condition in the well outside the casing with each of the plurality of sensors.

The method may comprise the step of transmitting acoustic signals indicative of the condition in the well to the first acoustic telemetry device with the second acoustic telemetry device. In embodiments where the acoustic telemetry system comprises a plurality of casing modules, the method may further comprise the step of transmitting acoustic signals indicative of the condition in the well with each of a plurality of second acoustic telemetry devices. In embodiments where each of the plurality of casing modules includes a sensor, each of the plurality of second acoustic telemetry devices may transmit signals indicative of the condition in the well measured by the corresponding sensor.

The method may comprise the step of receiving the acoustic signals transmitted through the casing with at least one first acoustic telemetry device.

In embodiments where the casing module further includes a rechargeable battery or a capacitor, the method may further comprise the steps of emitting acoustic waves with the first acoustic telemetry device, converting the acoustic waves into a DC voltage with the second acoustic telemetry device, and powering the sensor with the rechargeable battery or the capacitor.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more detailed description of the embodiments of the disclosure, reference will now be made to the accompanying drawings, wherein:

FIG. 1 is an elevation view, in cross-section, of an example of an acoustic telemetry system;

FIG. 2 is a top view, in cross-section, of the acoustic telemetry system shown in FIG. 1;

FIG. 3 is an elevation view, in cross-section, of another example of an acoustic telemetry system;

FIG. 4 is a top view, in cross-section, of the acoustic telemetry system shown in FIG. 3;

FIG. 5 is a view, in cross-section, of an example portion of an acoustic telemetry system, illustrating acoustic telemetry devices;

FIG. 6 is a view, in cross-section, of an example portion of an acoustic telemetry device, illustrating an acoustic transmitter; and

FIG. 7 is a view, in cross-section, of another example portion of an acoustic telemetry device, illustrating an acoustic receiver.

DETAILED DESCRIPTION

It is to be understood that the disclosure may repeat reference numerals and/or letters in the various exemplary embodiments and across the Figures provided herein. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various exemplary embodiments and/or configurations discussed in the various Figures. Additionally, the exemplary embodiments presented below may be combined in any combination of ways, i.e., any element from one exemplary embodiment may be used in any other exemplary embodiment, without departing from the scope of the disclosure. Finally, all numerical values in this disclosure may be approximate values unless otherwise specifically stated. Accordingly, various embodiments of the disclosure may deviate from the numbers, values, ranges, and proportions disclosed herein or illustrated in the Figures without departing from the intended scope.

This disclosure describes an acoustic telemetry system and a method of acoustic telemetry for transmitting signals from a sensor that monitors a condition in a well outside a casing. For example, the condition monitored by the sensor may inform a decision about the well's construction, such as casing exit and branching of the well into a lateral well and the main well, the well's production, or the well's abandonment. In some embodiments, the acoustic telemetry system and the method of acoustic telemetry can be used with a sensor that monitors the pressure in an annulus between a production casing and a next outer casing of a well, often referred to as the B-annulus.

In reference to FIGS. 1 and 2, a production casing 16 and a next outer casing 12 are constructed in a well that is formed into an Earth's formation 10. An acoustic telemetry system for receiving data from a sensor placed in a B-annulus 14, which is located between the production casing 16 and the next outer casing 12, is illustrated.

The acoustic telemetry system as shown in FIGS. 1 and 2 comprises a tool 18 conveyable inside the production casing 16. The tool 18 includes the first acoustic telemetry devices 26. Each of the first acoustic telemetry devices 26 is configured to receive acoustic signals from a second acoustic telemetry device 24.

Each of the first acoustic telemetry devices 26 is mounted on one of the arms 20, which are positioned around a periphery of the tool 18 and coupled to the tool 18. For example, five arms 20 may be distributed uniformly around the periphery of the tool 18; however, fewer or more than five arms may be coupled to the tool 18, and the arms may not be distributed uniformly around the periphery of the tool 18. Furthermore, each of the arms 20 further includes several acoustic telemetry modules 26 positioned along a longitudinal axis of the tool 18. For example, nine first acoustic telemetry devices 26 are mounted on each one of the arms 20 at regular intervals of six inches and span a total length of four feet. However, fewer or more than nine first acoustic telemetry devices can be mounted on each of the arms 20, the intervals between the first acoustic telemetry devices may be smaller or bigger than six inches and/ or be irregular. Preferably, but not necessarily, the first acoustic telemetry devices span a total length that is between four and five feet. Also, while the arms 20 are illustrated straight in FIGS. 1 and 2, the arms 20 may be curved.

Each of the arms 20 is extendable from the tool 18 toward the inner surface of the production casing 16, such that each of the first acoustic telemetry devices 26 can be pressed against the inner surface of the production casing 16.

The acoustic telemetry system as shown in FIGS. 1 and 2 further comprises a casing module 22, which may include a sensor (not shown) capable of measuring a condition in the well outside the casing. For example, the sensor may include a pressure gauge capable of measuring pressure in the B-annulus 14. However, other types of sensors may be included in the casing module 22. The casing module 22 includes the second acoustic telemetry device 24. The second acoustic telemetry device 24 is pressed against an outer surface of the production casing 16. The second acoustic telemetry device 24 is capable of transmitting acoustic signals indicative of the condition in the well measured by the sensor through the production casing 16 at least to any one of the first acoustic telemetry devices 26 that is located in the proximity of the second acoustic telemetry device 24 (e.g., less than six inches away from it).

While only one casing module 22 is illustrated in FIGS. 1 and 2, additional casing modules 22, each including a second acoustic telemetry device 24, may optionally be provided.

In use, the tool 18 shown in FIGS. 1 and 2 is positioned inside the production casing 16 such that at least one of the first acoustic telemetry devices 26 is located less than six inches away from the second acoustic telemetry device 24 after each of the arms 20 are extended from the tool 18 toward the inner surface of the production casing 16 and each of the first acoustic telemetry devices 26 is pressed against the inner surface of the production casing 16. Such proximity can ensure that the at least one of the first acoustic telemetry devices 26 will pick up the acoustic signals transmitted by the second acoustic telemetry device 24 through the production casing 16. In contrast with known systems, achieving such proximity is facilitated by the distribution of the arms 20 around the periphery of the tool 18 and/or the several first acoustic telemetry modules 26 regularly positioned along the longitudinal axis of the tool 18 on each arm 20.

A condition (e.g., pressure) of the well is measured in the B-annulus 14 with the sensor. The second acoustic telemetry device 24 transmits acoustic signals indicative of the condition in the well measured by the sensor to at least one of the first acoustic telemetry devices 26 that is located less than six inches away from the second acoustic telemetry device 24. The first acoustic telemetry devices 26 that are located less than six inches away from the second acoustic telemetry device 24 receive the acoustic signals transmitted through the production casing 16. However, additional first acoustic telemetry devices 26 may also receive the acoustic signals transmitted through the production casing 16. In contrast with known systems, the transmission of the signal through the production casing 16 can be facilitated by the first acoustic telemetry devices 26 being pressed against the inner surface of the production casing 16.

In reference to FIGS. 3 and 4, another acoustic telemetry system is illustrated.

The acoustic telemetry system as shown in FIGS. 3 and 4 comprises a tool 18 conveyable inside the production casing 16. The tool 18 includes a first acoustic telemetry device 26 that is configured to receive acoustic signals from any second acoustic telemetry devices 24. Each of the second acoustic telemetry devices 24 is configured to transmit acoustic signals indicative of a condition in the well.

The first acoustic telemetry device 26 is mounted on an arm 20 coupled to the tool 18. The arm 20 is extendable from the tool 18 toward an inner surface of the production casing 16 such that the first acoustic telemetry device 26 can be pressed against the inner surface of the production casing 16.

The acoustic telemetry system as shown in FIGS. 3 and 4 further comprises casing modules 22. Each of the casing modules 22 includes a corresponding one of the second acoustic telemetry devices 24. In some embodiments, each casing module 22 includes a corresponding sensor, each sensor is capable of measuring the condition in the well outside the production casing 16, and each of the second acoustic telemetry devices 24 is configured to transmit acoustic signals indicative of the condition in the well measured by the corresponding sensor. In other embodiments, fewer casing modules 22 include a sensor, and the sensor(s) are connected (e.g., wired) to other casing modules 22. Each of the second acoustic telemetry devices 24 is configured to transmit acoustic signals indicative of the condition in the well measured by the sensor it is connected to.

Each of the second acoustic telemetry devices 24 is pressed against the outer surface of the production casing 16. The second acoustic telemetry devices 24 are positioned around a periphery of the production casing 16 and along a longitudinal axis of the production casing 16. For example, eight columns of second acoustic telemetry devices 24 may be distributed uniformly around the periphery of the production casing 16, and each column of second acoustic telemetry devices 24 may consist of nine second acoustic telemetry devices 24 that are aligned vertically at regular intervals of six inches and span a total length of four feet. However, fewer or more than eight columns of second acoustic telemetry devices may be positioned around the periphery of the production casing 16, and the columns of second acoustic telemetry devices may not be distributed uniformly around the production casing 16. Also, each column may consist of fewer or more than nine second acoustic telemetry devices, the intervals between second acoustic telemetry devices in each column may be smaller or bigger than six inches and/or be irregular. Preferably, but not necessarily, the array of second acoustic telemetry devices may span a total length that is between four and five feet. Also, the second acoustic telemetry devices may not be aligned vertically or horizontally, such as, for example, in a spiral pattern or in a checkboard pattern.

While only one arm 20 that includes a single first acoustic telemetry device 26 is illustrated in FIGS. 3 and 4, additional first acoustic telemetry devices 26 may optionally be provided in the arm 20, and/or additional arms 20 that include one or more first acoustic telemetry devices 26 may optionally be provided.

In use, the tool 18 shown in FIGS. 3 and 4 is positioned inside the production casing 16 such that at least one of the second acoustic telemetry devices 24 is located less than six inches away from the first acoustic telemetry device 26 after the arm 20 is extended from the tool 18 toward the inner surface of the production casing 16 and the first acoustic telemetry device 26 is pressed against the inner surface of the production casing 16. Such proximity can ensure that the first acoustic telemetry device 26 will pick up the acoustic signals transmitted by at least one of the second acoustic telemetry devices 24 through the production casing 16. In contrast with known systems, achieving such proximity is facilitated by the array of second acoustic telemetry devices 24 positioned around the periphery of the tool 18 and/or along the longitudinal axis of the production casing 16.

A condition (e.g., pressure) of the well is measured in the B-annulus 14 with one or more sensors included in one or more casing modules 22. Each of the second acoustic telemetry device 24 transmits acoustic signals indicative of the condition in the well measured by a sensor it is connected to, preferably simultaneously for each sensor and sequentially for different sensors. The first acoustic telemetry device 26 receives the acoustic signals transmitted through the production casing 16 by at least one second acoustic telemetry device 24 that is located less than six inches away from the first acoustic telemetry device 26. However, the first acoustic telemetry device 26 can also receive the acoustic signals transmitted through the production casing 16 by other second acoustic telemetry devices. In contrast with known systems, the transmission of the signal through the production casing 16 can be facilitated by the first acoustic telemetry devices 26 being pressed against the inner surface of the production casing 16.

In reference to FIG. 5, an arm 20 of a tool is shown extended toward an inner surface of a production casing 16, and a casing module 22 is coupled to an outer surface of the production casing 16. First and second acoustic telemetry devices 26 and 24, which are respectively included in the arm 20 and the casing module 22, are illustrated.

In order to receive acoustic signals from the second acoustic telemetry device 24, the first acoustic telemetry device 26 includes an acoustic receiver 40. Referring briefly to FIG. 7, the acoustic receiver 40 includes, for example, one or more sensing elements 56 embedded in a matching layer 54, and a backing layer 58. The one or more sensing elements 56 have a size that is preferably small compared to a representative wavelength of the acoustic signals transmitted by the second acoustic telemetry device 24. When more than one sensing element 56 is used, the sensing elements 56 are preferably spread apart to increase the sensitivity area of the acoustic receiver 40. The matching layer 54 has an acoustic impedance that preferably maximizes the transmission of acoustic signals from the production casing 16, usually made of steel, to the sensing elements 56, usually made of piezoelectric material. The backing layer 58 is preferably designed to minimize reflections of the acoustic signals that could interfere with the direct acoustic signals.

The one or more sensing elements 56 are provided with at least one wire pair 60. Optionally, each sensing element 56 is provided with a dedicated wire pair 60. The at least one wire pair 60, or each dedicated wire pair 60, is connected to the receiver electronics 38 that digitizes the signal sensed by the one or more sensing elements 56.

The tool 18 collects the digitized signals from each of the first acoustic telemetry devices 26. Electronics in the tool 18 analyzes the digitized signals, identifies at least one of the first acoustic telemetry devices 26 that has received acoustic signal indicative of a condition in a well that is measured outside the production casing 16. As is well known, the tool 18 broadcasts, in turn, the measured condition in the well to the Earth's surface where the measurement can be used.

In order to transmit acoustic signals indicative of a condition in the well measured by the sensor 32 (e.g., a pressure gauge) to the first acoustic telemetry device 26, the second acoustic telemetry device 24 includes an acoustic transmitter 36. Referring briefly to FIG. 6, the acoustic transmitter 36 includes, for example, a stack of actuating elements 46 that is interposed between a matching layer 44 and a backing layer 48. The stack of actuating elements 46 has a size sufficient to generate acoustic signals that traverse the production casing 16. The matching layer 44 has an acoustic impedance that preferably maximizes the transmission of acoustic signals from the stack of actuating elements 46, usually made of piezoelectric material, to the production casing 16, usually made of steel. The backing layer 48 is preferably designed to minimize reflections of the acoustic signals that could interfere with the direct acoustic signals. Optionally, the stack of actuating elements 46, and consequently the transmitter 44, may be tilted by an angle 50 relative to the normal of the outer surface of the production casing 16. For example, angle 50 is selected to maximize the amplitude of the acoustic signals transmitted by the second acoustic telemetry device 24 through the production casing 16.

The stack of actuating elements 46 are connected to drive electronics 28 via wires 52. The drive electronics 28 includes a power source, such as a rechargeable battery or a capacitor. The drive electronics 28 receives a signal from the sensor 32, encodes the condition in the well measured by the sensor 32, and drives the stack of actuating elements 46 to generate the signal indicative of the condition in the well.

Preferably, but not necessarily, the drive electronics 28 is in sleep mode most of the time, such that the energy of the power source is preserved. In order to wake the drive electronics 28 up, the first acoustic telemetry device 26 may be provided with an acoustic transmitter 42, which may be designed according to principles similar to the principles described for designing the acoustic transmitter 36. The first acoustic telemetry device 26 can thus emit acoustic waves.

The acoustic waves emitted by the first acoustic telemetry device 26 may be sensed by an acoustic receiver 34 provided in the second acoustic telemetry device 24. The acoustic receiver 34 may be designed according to principles similar to the principles described for designing the acoustic receiver 40. When in sleep mode, the drive electronics 28 may only power the receiver electronics 30. Upon detecting acoustic waves, the receiver electronics 30 may wake the drive electronics 28 up. When woken up, the drive electronics 28 may sequentially power the sensor 32, measure a condition of the well, cause the acoustic transmitter 36 to transmit acoustic signals indicative of the condition measured by the sensor 32 through the production casing 16, and revert to sleep mode.

Alternatively, the acoustic waves emitted by the first acoustic telemetry device 26 may be converted into a DC voltage using energy harvesting electronics coupled to the stack of actuating elements 46. For example, the energy harvesting electronics can include a coil that matches the impedance of the stack of actuating elements 46 at the main frequency of the acoustic waves generated by the first acoustic telemetry device 26, and a bridge rectifier coupled between the coil and the power source of the drive electronics. The first acoustic telemetry device 26 may emit acoustic waves for a duration sufficient to charge a rechargeable battery or a capacitor such that the rechargeable battery or the capacitor can power the drive electronics 28, the sensor 32, and then, the acoustic transmitter 36, before the drive electronics 28 reverts to sleep mode. In such cases, the acoustic receiver 34 may be omitted, and the acoustic transmitter 36 is effectively used as an acoustic receiver also.

While FIG. 5 shows a sensor 32 included in the same casing module 22 as the second acoustic telemetry device 24, the sensor 32 may be located elsewhere and/or may be connected to multiple acoustic telemetry devices 24 included in respective casing modules 22.

In some embodiments, the actuating elements 46 shown in FIG. 6 may sequentially be coupled to drive electronics and receiver electronics. As such, the actuating elements 46 may be used as actuating elements or sensing elements. In such embodiments, the acoustic receiver 40 shown in the first acoustic telemetry device 26 of FIG. 5 and/or the receiver 34 shown in the second acoustic telemetry device 24 of FIG. 5 may be omitted. In other words, the acoustic transmitter 42 and the acoustic receiver 40 and/or the acoustic transmitter 36 and the acoustic receiver 34 may be integrated into acoustic transceiver(s).

While FIGS. 5 and 6 show an example of an acoustic transmitter, other known types of acoustic transmitters may be used to implement in an acoustic telemetry device. Also, while FIGS. 5 and 7 show an example of an acoustic receiver, other known types of acoustic receivers may be used to implement in an acoustic telemetry device.

In addition to the foregoing, the disclosure also contemplates at least the following embodiments:

Embodiment 1

Embodiment 1 is an acoustic telemetry system for transmitting signals from a sensor that is capable of measuring a condition in the well outside a casing. The acoustic telemetry system comprises a tool conveyable inside a casing of a well and a casing module including the sensor.

Generally, the tool includes a first acoustic telemetry device. The casing module includes a second acoustic telemetry device. The second acoustic telemetry device is capable of transmitting acoustic signals indicative of the condition in the well measured by the sensor through the casing and to the first acoustic telemetry device. The first acoustic telemetry device is capable of receiving acoustic signals from the second acoustic telemetry device.

For example, the first acoustic telemetry device is mounted on an arm coupled to the tool. The arm is extendable from the tool toward an inner surface of the casing such that the first acoustic telemetry device is pressed against the inner surface of the casing. The second acoustic telemetry device is pressed against an outer surface of the casing.

Embodiment 2

Embodiment 2 is a system as described in embodiment 1, wherein the tool further includes a plurality of first acoustic telemetry devices. Each of the plurality of first acoustic telemetry devices is configured to receive acoustic signals from the second acoustic telemetry device.

Generally, each of the plurality of first acoustic telemetry devices is mounted on a respective one of a plurality of arms. For example, the plurality of arms are positioned around a periphery of the tool. Each of the plurality of arms is coupled to the tool and extendable from the tool toward the inner surface of the casing such that each of the plurality of first acoustic telemetry devices is pressed against the inner surface of the casing.

Embodiment 3

Embodiment 3 is a system as described in embodiment 1 or 2, wherein the arm, one of the plurality of arms, or each of the plurality of arms, further includes several acoustic telemetry modules positioned along a longitudinal axis of the tool.

Generally, the arm, one of the plurality of arms, or each of the plurality of arms is extendable from the tool toward the inner surface of the casing, for example, such that each of the several acoustic telemetry modules is pressed against the inner surface of the casing.

Embodiment 4

Embodiment 4 is a system as described in any of embodiments 1 to 3, further comprising a plurality of casing modules. The plurality of second acoustic telemetry devices are positioned around a periphery of the casing. Each of the plurality of casing modules includes a corresponding one of a plurality of second acoustic telemetry devices.

Generally, each of the plurality of second acoustic telemetry devices is configured to transmit acoustic signals indicative of the condition in the well. For example, each of the plurality of second acoustic telemetry devices is pressed against the outer surface of the casing, and

Embodiment 5

Embodiment 4 is a system as described in embodiment 4, wherein each of the plurality of casing modules includes a corresponding one of a plurality of sensors.

Generally, each of the plurality of sensors is capable of measuring the condition in the well outside the casing, and each of the plurality of second acoustic telemetry devices is configured to transmit acoustic signals indicative of the condition in the well measured by the corresponding one of the plurality of sensors.

Embodiment 6

Embodiment 6 is a system as described in any of embodiments 1 to 5, wherein the first acoustic telemetry device, at least one of the plurality of first acoustic telemetry devices, or each of the plurality of first acoustic telemetry devices is further capable of emitting acoustic waves. The second acoustic telemetry device, at least one of the plurality of second acoustic telemetry devices, or each of the plurality of second acoustic telemetry devices is further capable of converting the acoustic waves into a DC voltage.

Generally, the casing module, at least one of the plurality of casing modules, or each of the plurality of casing modules further includes a rechargeable battery or a capacitor coupled to the DC voltage. The sensor, at least one of the plurality of sensors, or each of the plurality of sensors is powered by a rechargeable battery or a capacitor.

Embodiment 7

Embodiment 7 is a system as described in any of embodiments 1 to 6, wherein the second acoustic telemetry device, at least one of the plurality of second acoustic telemetry devices, or each of the plurality of second acoustic telemetry devices comprises a piezoelectric material.

Embodiment 8

Embodiment 8 is a method of acoustic telemetry for transmitting signals from a sensor. The method comprises the step of positioning a tool inside a casing of a well. Generally, the tool is part of a system as described in any of embodiments 1 to 7. For example, the tool includes a first acoustic telemetry device, and the first acoustic telemetry device is mounted on an arm coupled to the tool. The method comprises the step of extending the arm from the tool toward an inner surface of the casing. Preferably, the first acoustic telemetry device, at least one of the plurality of first acoustic telemetry devices, or each of the plurality of first acoustic telemetry devices is pressed against the inner surface of the casing. The method comprises the step of measuring a condition in the well outside the casing with a sensor. Generally, the sensor is included in a casing module that is part of a system as described in any of embodiments 1 to 7. For example, the casing module includes a second acoustic telemetry device that is pressed against an outer surface of the casing. The method comprises the step of transmitting acoustic signals indicative of the condition in the well measured by the sensor to the first acoustic telemetry device, at least one of the plurality of first acoustic telemetry devices, or each of the plurality of first acoustic telemetry devices. The acoustic signals are transmitted using the second acoustic telemetry device, at least one of the plurality of second acoustic telemetry devices, or each of the plurality of second acoustic telemetry devices. The method comprises the step of receiving the acoustic signals transmitted through the casing with the first acoustic telemetry device, at least one of the plurality of first acoustic telemetry devices, or each of the plurality of first acoustic telemetry devices.

Embodiment 9

Embodiment 9 is a method as described in embodiment 8, further comprising the step of extending each of a plurality of arms from the tool toward the inner surface of the casing. Preferably, each of the plurality of first acoustic telemetry devices is pressed against the inner surface of the casing. Preferably, the tool is positioned inside the casing of the well such that at least one of the plurality of first acoustic telemetry devices is located less than six inches away from the second acoustic telemetry device, or at least one of the plurality of second acoustic telemetry devices. Preferably, the acoustic signals transmitted from the second acoustic telemetry device or the at least one of the plurality of second acoustic telemetry devices are received by the at least one of the plurality of first acoustic telemetry devices.

Embodiment 10

Embodiment 9 is a method as described in embodiment 8 or 9, wherein each of the plurality of arms includes several acoustic telemetry modules positioned along a longitudinal axis of the tool, each of the plurality of arms being extendable from the tool toward the inner surface of the casing, preferably, so that each of the several acoustic telemetry modules is pressed against the inner surface of the casing.

Embodiment 11

Embodiment 11 is a method as described in any of embodiments 8 to 10, comprising the step of transmitting acoustic signals indicative of the condition in the well with each of a plurality of second acoustic telemetry devices, each of the plurality of second acoustic telemetry devices being included in a corresponding one of a plurality of casing modules.

Preferably, each of the plurality of second acoustic telemetry devices is pressed against the outer surface of the casing, the plurality of second acoustic telemetry devices are positioned around a periphery of the casing, the tool is positioned inside the casing of the well such that at least one of the plurality of second acoustic telemetry devices is located less than six inches away from the first acoustic telemetry device, and the first acoustic telemetry device receives the acoustic signals transmitted from the at least one of the plurality of second acoustic telemetry devices.

Embodiment 12

Embodiment 12 is a method as described in any of embodiments 8 to 11, further comprising the step of measuring the condition in the well outside the casing with each of the plurality of sensors, wherein each of the plurality of second acoustic telemetry devices transmits signals indicative of the condition in the well measured by the corresponding one of the plurality of sensors.

Embodiment 13

Embodiment 13 is a method as described in any of embodiments 8 to 12, further comprising the steps of emitting acoustic waves with the first acoustic telemetry device, at least one of the plurality of first acoustic telemetry devices, or each of the plurality of first acoustic telemetry devices, converting the acoustic waves into the DC voltage with the second acoustic telemetry device, at least one of the plurality of second acoustic telemetry devices, or each of the plurality of second acoustic telemetry devices, and powering the sensor, at least one of the plurality of sensors, or each of the plurality of sensors, with a rechargeable battery or a capacitor.

Embodiment 14

Embodiment 14 is a method as described in any of embodiments 8 to 13, wherein the second acoustic telemetry device, at least one of the plurality of second acoustic telemetry devices, or each of the plurality of second acoustic telemetry devices comprises a piezoelectric material.

The claimed invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and description. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the claims to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the claims. 

What is claimed is:
 1. An acoustic telemetry system for transmitting signals from a sensor, the system comprising: a tool conveyable inside a casing of a well, the tool including a first acoustic telemetry device, the first acoustic telemetry device being capable of receiving acoustic signals from a second acoustic telemetry device, wherein the first acoustic telemetry device is mounted on an arm coupled to the tool, the arm being extendable from the tool toward an inner surface of the casing such that the first acoustic telemetry device is pressed against the inner surface of the casing; and a casing module including the sensor and the second acoustic telemetry device, the sensor being capable of measuring a condition in the well outside the casing, the second acoustic telemetry device being capable of transmitting acoustic signals indicative of the condition in the well measured by the sensor through the casing and to the first acoustic telemetry device, wherein the second acoustic telemetry device is pressed against an outer surface of the casing.
 2. The system of claim 1, wherein the tool further includes a plurality of first acoustic telemetry devices, each of the plurality of first acoustic telemetry devices being configured to receive acoustic signals from the second acoustic telemetry device, and wherein each of the plurality of first acoustic telemetry devices is mounted on a respective one of a plurality of arms, the plurality of arms being positioned around a periphery of the tool, each of the plurality of arms being coupled to the tool and extendable from the tool toward the inner surface of the casing such that each of the plurality of first acoustic telemetry devices is pressed against the inner surface of the casing.
 3. The system of claim 2, wherein each of the plurality of arms further includes several acoustic telemetry modules positioned along a longitudinal axis of the tool, each of the plurality of arms being extendable from the tool toward the inner surface of the casing such that each of the several acoustic telemetry modules is pressed against the inner surface of the casing.
 4. The system of claim 1, further comprising a plurality of casing modules, each of the plurality of casing modules including a corresponding one of a plurality of second acoustic telemetry devices, each of the plurality of second acoustic telemetry devices being configured to transmit acoustic signals indicative of the condition in the well, wherein each of the plurality of second acoustic telemetry devices is pressed against the outer surface of the casing, and wherein the plurality of second acoustic telemetry devices are positioned around a periphery of the casing.
 5. The system of claim 4, wherein each of the plurality of casing modules includes a corresponding one of a plurality of sensors, each of the plurality of sensors being capable of measuring the condition in the well outside the casing, each of the plurality of second acoustic telemetry devices being configured to transmit acoustic signals indicative of the condition in the well measured by the corresponding one of the plurality of sensors.
 6. The system of claim 1, wherein the first acoustic telemetry device is further capable of emitting acoustic waves, wherein the second acoustic telemetry device is further capable of converting the acoustic waves into a DC voltage, wherein the casing module further includes a rechargeable battery or a capacitor coupled to the DC voltage, and wherein the sensor is powered by the rechargeable battery or the capacitor.
 7. The system of claim 6, wherein the second acoustic telemetry device comprises a piezoelectric material.
 8. A method of acoustic telemetry for transmitting signals from a sensor, the method comprising: positioning a tool inside a casing of a well, the tool including a first acoustic telemetry device, wherein the first acoustic telemetry device is mounted on an arm coupled to the tool; extending the arm from the tool toward an inner surface of the casing such that the first acoustic telemetry device is pressed against the inner surface of the casing; measuring a condition in the well outside the casing with a sensor included in a casing module; transmitting acoustic signals indicative of the condition in the well measured by the sensor to the first acoustic telemetry device with the second acoustic telemetry device, wherein the second acoustic telemetry device is included in the casing module and is pressed against an outer surface of the casing; and receiving the acoustic signals transmitted through the casing with the first acoustic telemetry device.
 9. The method of claim 8, wherein the tool further includes a plurality of first acoustic telemetry devices, each of the plurality of first acoustic telemetry devices being configured to receive acoustic signals from the second acoustic telemetry device, and wherein each of the plurality of first acoustic telemetry devices is mounted on a respective one of a plurality of arms, each of the plurality of arms being coupled to the tool, the plurality of arms being positioned around a periphery of the tool, the method further comprising extending each of the plurality of arms from the tool toward the inner surface of the casing such that each of the plurality of first acoustic telemetry devices is pressed against the inner surface of the casing, wherein the tool is positioned inside the casing of the well such that at least one of the plurality of first acoustic telemetry devices is located less than six inches away from the second acoustic telemetry device, and wherein the acoustic signals transmitted from the second acoustic telemetry device are received by the at least one of the plurality of first acoustic telemetry devices.
 10. The method of claim 9, wherein each of the plurality of arms includes several acoustic telemetry modules positioned along a longitudinal axis of the tool, each of the plurality of arms being extendable from the tool toward the inner surface of the casing such that each of the several acoustic telemetry modules is pressed against the inner surface of the casing.
 11. The method of claim 8, comprising transmitting acoustic signals indicative of the condition in the well with each of a plurality of second acoustic telemetry devices, each of the plurality of second acoustic telemetry devices being included in a corresponding one of a plurality of casing modules, wherein each of the plurality of second acoustic telemetry devices is pressed against the outer surface of the casing, wherein the plurality of second acoustic telemetry devices are positioned around a periphery of the casing, wherein the tool is positioned inside the casing of the well such that at least one of the plurality of second acoustic telemetry devices is located less than six inches away from the first acoustic telemetry device, and wherein the first acoustic telemetry device receives the acoustic signals transmitted from the at least one of the plurality of second acoustic telemetry devices.
 12. The method of claim 11, wherein each of the plurality of casing modules includes a corresponding one of a plurality of sensors, the method further comprising measuring the condition in the well outside the casing with each of the plurality of sensors, wherein each of the plurality of second acoustic telemetry devices transmits acoustic signals indicative of the condition in the well measured by the corresponding one of the plurality of sensors.
 13. The method of claim 8, wherein the casing module further includes a rechargeable battery or a capacitor coupled to a DC voltage, the method further comprising: emitting acoustic waves with the first acoustic telemetry device; converting the acoustic waves into the DC voltage with the second acoustic telemetry device; and powering the sensor with the rechargeable battery or the capacitor.
 14. The method of claim 13, wherein the second acoustic telemetry device comprises a piezoelectric material. 